
public class Balloon {
	
	double volume = 0;
	//double radius = 0;
	
	public void addAir(double amount)
	{
	 volume = volume +  amount;   
	}

	public double getVolume()
	{
	    return volume;
	}

	public double getSurfaceArea()
	{
	    return 4*Math.PI*Math.pow((Math.pow((((3.0/4.0)*volume)/Math.PI), 1.0/3.0)),2);
	}

	public double getRadius()
	{
	    return Math.pow((((3.0/4.0)*volume)/Math.PI), 1.0/3.0);
	}

}
